The present invention relates to a gain adjustment method and a magnetic resonance imaging apparatus, and particularly, to a method of adjusting a gain for reception of a magnetic resonance signal and a magnetic resonance imaging apparatus equipped with gain adjusting means for reception of a magnetic resonance signal.
In a magnetic resonance imaging (MRI: Magnetic Resonance Imaging) apparatus, a gain is adjusted in such a manner that a receiving level of a magnetic resonance signal becomes proper. The adjustment of the gain is dynamically performed during one scan so as to prevent a reduction in an SNR (signal-to-noise ratio). A post-reception signal is normalized in accordance with to the gain, and image reconstruction is carried out based on the signal after the normalization (e.g., refer to the following patent literature 1).
[Patent Literature 1]
Specification of U.S. Pat. No. 5,451,876 (fifth to sixth columns and FIGS. 1 through 3)
There may be a case in which, when magnetic resonance imaging is carried out in real time, the imaging is done while a slice thickness and a field of view (FOV) are being changed in various ways. Since, however, the conventional gain adjustment is not associated with it, clipping or the like of a data due to an over range of an A/D converter occurs when the slice thickness and FOV have been increased, so that there is a problem that proper imaging cannot be carried out.